1. import matplotlib.pyplot as plt
3. # 定義文字框和箭頭格式
4. decisionNode = dict(boxstyle = "sawtooth", fc = "0.8")
5. leafNode = dict(boxstyle = "round4", fc = "0.8")
6. arrow_args = dict(arrowstyle = "<-")
8. # 繪製帶箭頭的註解
9. def plotNode(nodeTxt, centerPt, parentPt, nodeType) :
10. createPlot.ax1.annotate(nodeTxt, xy = parentPt, xycoords = 'axes fraction'
    , xytext = centerPt, textcoords = 'axes fraction', va = 'center', ha = 'center', bbox = nodeType, arrowprops = arrow_args)
12. def createPlot() :
13. fig = plt.figure( 1, facecolor= 'white')
14. fig.clf()
15. createPlot.ax1 = plt.subplot( 111, frameon = False)
16. plotNode(U '決策節點', ( 0.5, 0.1), ( 0.1, 0.5), decisionNode)
17. plotNode(U '葉節點', ( 0.8, 0.1), ( 0.3, 0.8), leafNode)
18. plt.show()
20. createPlot()

得到影象如下：

產生中文亂碼的原因就是字型的預設設定中並沒有中文字型，我們只要手動新增中文字型的名稱就可以了

手動增加如下程式碼

1. from pylab import *
2. mpl.rcParams[ 'font.sans-serif'] = [ 'SimHei']

1. import matplotlib.pyplot as plt
3. from pylab import *
4. mpl.rcParams[ 'font.sans-serif'] = [ 'SimHei']
6. # 定義文字框和箭頭格式
7. decisionNode = dict(boxstyle = "sawtooth", fc = "0.8")
8. leafNode = dict(boxstyle = "round4", fc = "0.8")
9. arrow_args = dict(arrowstyle = "<-")
11. # 繪製帶箭頭的註解
12. def plotNode(nodeTxt, centerPt, parentPt, nodeType) :
13. createPlot.ax1.annotate(nodeTxt, xy = parentPt, xycoords = 'axes fraction', xytext = centerPt, textcoords = 'axes fraction', va = 'center', ha = 'center', bbox = nodeType, arrowprops = arrow_args)
15. def createPlot() :
16. fig = plt.figure( 1, facecolor= 'white')
17. fig.clf()
18. createPlot.ax1 = plt.subplot( 111, frameon = False)
19. plotNode(U '決策節點', ( 0.5, 0.1), ( 0.1, 0.5), decisionNode)
20. plotNode(U '葉節點', ( 0.8, 0.1), ( 0.3, 0.8), leafNode)
21. plt.show()
22. createPlot()

完成!